@article { ISI:000220281000014, title = {Structural analysis of the sialyltransferase CstII from Campylobacter jejuni in complex with a substrate analog}, journal = {NATURE STRUCTURAL \& MOLECULAR BIOLOGY}, volume = {11}, number = {2}, year = {2004}, month = {FEB}, pages = {163-170}, abstract = {Sialic acid terminates oligosaccharide chains on mammalian and microbial cell surfaces, playing critical roles in recognition and adherence. The enzymes that transfer the sialic acid moiety from cytidine-5{\textquoteright}-monophospho-N-acetyl- neuraminic acid (CMP-NeuAc) to the terminal positions of these key glycoconjugates are known as sialyltransferases. Despite their important biological roles, little is understood about the mechanism or molecular structure of these membrane-associated enzymes. We report the first structure of a sialyltransferase, that of CstII from Campylobacter jejuni, a highly prevalent foodborne pathogen. Our structural, mutagenesis and kinetic data provide support for a novel mode of substrate binding and glycosyl transfer mechanism, including essential roles of a histidine ( general base) and two tyrosine residues ( coordination of the phosphate leaving group). This work provides a framework for understanding the activity of several sialyltransferases, from bacterial to human, and for the structure-based design of specific inhibitors.}, issn = {1545-9985}, doi = {10.1038/nsmb720}, author = {Chiu, CPC and Watts, AG and Lairson, LL and Gilbert, M and Lim, D and WAKARCHUK, WW and Withers, SG and Strynadka, NCJ} }